1. Field of the Invention
This invention relates to a partially prefabricated structural concrete beam and method therefor.
2. Description of Related Art
Structural concrete includes prestressed concrete, post-tensioned concrete, reinforced concrete, and plain concrete, among others. The use of prefabricated structural concrete elements in bridge and building construction is an accepted means for achieving certain advantages. For example, use of such elements may speed construction and/or lower overall costs. It may also be safer for workers to erect a prefabricated concrete element as compared to pouring a similar concrete element in-place.
Commonly, a plurality of flat prefabricated concrete panels are utilized to construct the deck portion of a roadway bridge; these panels typically span between longitudinal support members and are most often topped with a depth of concrete which ties the structure together and completes the roadway surface. Prefabricated concrete members are also commonly utilized in bridge construction to span across or between support columns, or to span longitudinally in support of the deck. Such prefabricated members commonly are designed such that small sections of less than ten percent of the total weight of the member are poured-in-place in the field in order to complete the needed connections between the prefabricated member and other elements of the structure, such as columns or walls. The use of such large prefabricated concrete members, therefore, is of significantly reduced benefit due to their sheer size, weight, and handling difficulties.
The known prior art methods of bridge construction do not integrate, in a single beam member, prefabricated structural concrete with poured-in-place structural concrete in the manner of the present invention. In view of the prior art, a method of beam construction is needed by which a single structural concrete beam, such as an “inverted-T” bent cap, for example, beneficially utilizes both prefabricated structural concrete and poured-in-place structural concrete along a significant portion of the length of the beam.